The present invention relates to a brake assembly, and more particularly to an autonomous generation brake assembly in which an armature coil and a permanent magnet is incorporated for generating electricity at one hand, and a magnetic coil is incorporated for generating magnetic force for braking an exterior rotor.
A conventional autonomous generation brake generally includes a dynamo mounted on a spindle of a sport bike, a rectifier and a braking system enclosing the dynamo. When the wheel is rotated, the dynamo is actuated thereby generating electricity. The electricity then flows through the rectifier, and then directs to a magnetic coil thereby generating magnetic force which in turn attracts a drum enclosing the magnetic coils thereby stopping the rotation of the drum.
U.S. Pat. No. 5,986,370 to Cheng discloses a typical autonomous generation brake, as shown in FIGS. 5 and 6 of the attached drawings. An armature coils and a magnetic coils are mounted to first and second stators (A, B), respectively, i.e. there are configured by different members. The first stator (A) in which the armature coils mounted is configured by the armature coils (a3) sandwiched between first and second braking members (a1, a2). While the second stator (B) in which the magnetic coils mounted is configured by a magnetic coils (b3) sandwiched between third and fourth braking members (b1, b2) which is larger then the first and second braking members (a1, a2) in dimension. Then the first and second stators (A, B) are assembled to first and second rotors (C, D) to complete the assembly. Even the autonomous generation brake disclosed in the ""370 patent does achieve to its intended purpose, the complicated structure inevitably increase its cost. In addition, this brake assembly is too large to incorporate to the bicycle.
It is an objective of this invention to provide an autonomous brake assembly in which a stator including an armature coils and a magnetic coils. The armature coils works with a first rotor for including electrical current, and the magnetic coils is energized to generate magnetic force to hold down an interior second rotor.
In order to achieve the objective set forth, an autonomous generation brake assembly in accordance with the present invention comprises a hub acting as a first rotor and defines a receiving space therein by a peripheral wall. A plurality of permanent magnets are arranged alternatively along inner face of the peripheral wall. A stator is received in the receiving space of the hub and includes an armature coils corresponding to the permanent magnets of the hub, and a magnetic coils. A second rotor is rotationally received in the hub and located within the stator for working with the magnetic coils thereby generating eddy current therein for being attracted by the magnetic coils of the stator.
According to another aspect of the present invention, wherein the stator is configured by a plurality of yoke iron shims thereby decreasing the manufacturing cost. In addition, the braking capacity can be readily adjusted by the dimension of the yoke iron shims.
According to another aspect of the present invention, wherein the magnetic coils can be configured firstly, then assembled to cores formed on the stator thereby reducing the labor cost.